On the subject of hour-to-hour productivity, the Pomodoro Technique works well for me. Basically, you just set aside 40 minutes or so of completely uninterrupted time. If there's something that pops into your head, just write it down and do it later. When the 40 minutes are up, you've completed one pomodoro.

I find that I want to complete as many Pomodoro's as I can, sorta like a game.